The growth of wireless communications has resulted in a large number of different standards operating in different portions of the spectrum. Software defined radios (SDRs) have been proposed so a single device can operate with different standards or frequencies. Their implementation remains an active area of research given the challenging performance requirements in terms of noise figure (NF), linearity, and power dissipation. Multi-standard receivers are often designed to meet the worst-case combination of requirements which leads to increased power dissipation. Given the continued growth in usage and data rates of wireless devices, the amount of interference that receivers need to tolerate keeps increasing, while the spectral conditions can also vary significantly from location to location and from time to time. Therefore it is becoming more and more desirable to design radio frequency (RF) front ends that can dynamically adjust to the specific spectral operating conditions and standards.
Accordingly, new circuits for radio receivers are desirable.